For long term I would invest in equities--whether that was through ETFs, individual stocks, or mutual funds. Of course that depends on your competency, willingness to look at your asset allocations periodically, if you want a hands off approach etc.
If I didn't want to look at the stock market or manage my portfolio myself (and I'm not talking daytrading but taking a look at the end of every 6 months or a year and rebalancing) then I'd go with a good mutual fund that invests in a diverse set of equities--both foreign and domestic, large and small cap etc.--and possibly bonds/money market funds.
I'd be one of those "nuts" that keeps investing in equities through thick and thin because I know eventually it will rise and my money will go up with it. Always has before and I'm willing to take risk to gain a higher rate of return. Its generally best to invest when its low.
